from __future__ import annotations
from PyQt6.QtWidgets import (
    QWidget, QVBoxLayout, QHBoxLayout, QLabel, QGridLayout, QFrame, QSizePolicy
)
from PyQt6.QtCore import Qt, QTimer, pyqtSignal, QThread
from PyQt6.QtGui import QFont
from utils.formatters import fmt_currency, fmt_percent, pnl_color

INDICES = [
    ("SPY", "S&P 500"),
    ("QQQ", "NASDAQ 100"),
    ("DIA", "Dow Jones"),
    ("BTC-USD", "Bitcoin"),
    ("ETH-USD", "Ethereum"),
]


class QuoteCard(QFrame):
    clicked = pyqtSignal(str)

    def __init__(self, symbol: str, name: str, parent=None):
        super().__init__(parent)
        self.symbol = symbol
        self.setObjectName("card")
        self.setCursor(Qt.CursorShape.PointingHandCursor)
        self.setSizePolicy(QSizePolicy.Policy.Expanding, QSizePolicy.Policy.Fixed)
        self.setMinimumHeight(100)

        layout = QVBoxLayout(self)
        layout.setContentsMargins(12, 10, 12, 10)
        layout.setSpacing(2)

        top = QHBoxLayout()
        self._symbol_label = QLabel(symbol)
        self._symbol_label.setFont(QFont("Segoe UI", 10, QFont.Weight.Bold))
        self._name_label = QLabel(name)
        self._name_label.setObjectName("subtitle")
        self._name_label.setAlignment(Qt.AlignmentFlag.AlignRight)
        top.addWidget(self._symbol_label)
        top.addWidget(self._name_label)
        layout.addLayout(top)

        self._price_label = QLabel("—")
        self._price_label.setFont(QFont("Segoe UI", 16, QFont.Weight.Bold))
        layout.addWidget(self._price_label)

        self._change_label = QLabel("—")
        self._change_label.setObjectName("subtitle")
        layout.addWidget(self._change_label)

    def update_quote(self, data: dict):
        price = data.get("price", 0)
        change = data.get("change", 0)
        change_pct = data.get("change_pct", 0)
        self._price_label.setText(fmt_currency(price))
        sign = "+" if change >= 0 else ""
        self._change_label.setText(f"{sign}{fmt_currency(change, 2)}  {fmt_percent(change_pct, plus=True)}")
        color = pnl_color(change)
        self._change_label.setStyleSheet(f"color: {color};")

    def mousePressEvent(self, event):
        self.clicked.emit(self.symbol)
        super().mousePressEvent(event)


class FetchWorker(QThread):
    quotes_ready = pyqtSignal(dict)

    def __init__(self, symbols: list[str]):
        super().__init__()
        self._symbols = symbols

    def run(self):
        from core.market_data import get_batch_quotes
        data = get_batch_quotes(self._symbols)
        self.quotes_ready.emit(data)


class DashboardWidget(QWidget):
    symbol_selected = pyqtSignal(str)

    def __init__(self, parent=None):
        super().__init__(parent)
        self._cards: dict[str, QuoteCard] = {}
        self._worker: FetchWorker | None = None
        self._setup_ui()
        self._start_refresh()

    def _setup_ui(self):
        root = QVBoxLayout(self)
        root.setContentsMargins(20, 20, 20, 20)
        root.setSpacing(16)

        header = QLabel("Market Overview")
        header.setObjectName("title")
        root.addWidget(header)

        self._status_label = QLabel("Refreshing...")
        self._status_label.setObjectName("subtitle")
        root.addWidget(self._status_label)

        grid = QGridLayout()
        grid.setSpacing(12)
        for i, (symbol, name) in enumerate(INDICES):
            card = QuoteCard(symbol, name)
            card.clicked.connect(self.symbol_selected)
            self._cards[symbol] = card
            grid.addWidget(card, i // 3, i % 3)

        root.addLayout(grid)
        root.addStretch()

    def _start_refresh(self):
        self._timer = QTimer(self)
        self._timer.timeout.connect(self._fetch_quotes)
        self._timer.start(300_000)  # 5 min
        self._fetch_quotes()

    def _fetch_quotes(self):
        if self._worker and self._worker.isRunning():
            return
        self._status_label.setText("Refreshing...")
        self._worker = FetchWorker([s for s, _ in INDICES])
        self._worker.quotes_ready.connect(self._on_quotes_ready)
        self._worker.start()

    def _on_quotes_ready(self, data: dict):
        from datetime import datetime
        for sym, quote in data.items():
            if sym in self._cards:
                self._cards[sym].update_quote(quote)
        self._status_label.setText(f"Updated {datetime.now().strftime('%H:%M:%S')}  (15-min delayed)")

    def force_refresh(self):
        self._fetch_quotes()